[Date Prev][Date Next]
Re: openldap 2.4.16 hangs with dncachesize smaller than max number of records
- To: firstname.lastname@example.org
- Subject: Re: openldap 2.4.16 hangs with dncachesize smaller than max number of records
- From: Rodrigo Costa <email@example.com>
- Date: Wed, 17 Jun 2009 18:09:30 -0700 (PDT)
- Cc: firstname.lastname@example.org
- Dkim-signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yahoo.com; s=s1024; t=1245287370; bh=DBXvLWhZLOETu77qdWqUekus2u2tLC91tOn2UeA2Rs0=; h=Message-ID:X-YMail-OSG:Received:X-Mailer:Date:From:Subject:To:Cc:MIME-Version:Content-Type; b=q05b7yAk4/80RYWmuCkDN3AZ0b/xLh0tAnntdE9lkON3GKko/xlAIxEdKpadxoWtvQ9Ha7RpCwmCuMiod0tLteqRysaX33Qrz7A1wJyfEq7FAt2xs4GlpeMTAJVXpxaMghlQDB7FQChhIclOmoY3Tt/YNd0rGMggnv6a7ZXRlFE=
- Domainkey-signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com; h=Message-ID:X-YMail-OSG:Received:X-Mailer:Date:From:Subject:To:Cc:MIME-Version:Content-Type; b=btmfGFZZalmh0teoyBxvF9Q1QmVwcNOv+Xy5szD1eDgNLuGfr+TbA1qPWaQLJQcmimjhsDaMg1T6GLjzSHjE4j0MNBt0FN1Ix9OrcIvsiExvk9RB8h62YCvrQfDY3MUeUo3Z4fkINJGtkGSWrKWI9crOCFgSHscF3KmatGmYVlA=;
Maybe I'm not understanding very well your explanation.
What I can see is that until the dncache is filled any search can be
done very fast. After this is filled even stopping the original search
and starting a new one the pace is now very slow with some queries
taking around 8 seconds to end.
Once dncache is filled is there any configuration like cachefree that
could make the searches become similar to the original pace?
Howard Chu wrote:
> Rodrigo Costa wrote:
>> The idea was exactly to use the dncachesize large so the search or
>> random database access would not be affected.
>> The issue is that after DB is filled any search hangs time by time even
>> there are many entrances into cache. I was expecting that to remove or
>> re-cache an entrance some performance affectance would occur but if
>> ldapsearch would be stopped and a new one started the search would be
>> faster since there are millions of entrances already cached.
> Except that there *aren't* million of entries already cached, you've
> only cached a few thousand entries. And when you have such a tiny
> fraction of the database cached, the cache is going to be mostly
> useless for random access patterns. At this point you're making me
> repeat myself, so I'm stopping here.
> By the way, an "entrance" is a doorway. A directory object is an
> "entry" ...
> -- -- Howard Chu
> CTO, Symas Corp. http://www.symas.com
> Director, Highland Sun http://highlandsun.com/hyc/
> Chief Architect, OpenLDAP http://www.openldap.org/project/